Wheathampstead House

You'll find the earthworks of Wheathampstead House just outside St Albans, though calling it a 'house' now is generous - what remains are the defensive ditches and banks of an Iron Age settlement dating back around 2,000 years. The site sits on open ground where you can walk the perimeter and get a real sense of how those ancient inhabitants arranged their defences, which is more engaging than it sounds once you start imagining the settlement that once thrived here.

The location matters. This wasn't some random spot - it's positioned strategically on higher ground, and standing there you understand why. History buffs will appreciate that this is where Cassivelaunus, a British tribal leader, made his stand against Julius Caesar's invasion in 54 BC. It's one of those places where you're literally walking over events that changed the course of British history.

Walking it takes maybe 30-45 minutes depending on how contemplative you're feeling. There's no visitor centre or facilities to speak of, so come prepared - it's pretty exposed if weather turns. The nearby campsite at Commons Wood (5 miles away) and the highly-rated Cherry Green Trees (5.3 miles) both work well as bases if you're doing a Hertfordshire park break. St Albans itself is close enough for a proper day out combining this site with the cathedral and Roman remains in town.

Kids aged 8+ might engage with it if they're interested in archaeology; younger ones will probably find it a bit abstract. Go in late afternoon light when the earthworks cast shadows - it makes the scale of the thing much clearer.